Cover - USD ($)	12 Months Ended
	Dec. 31, 2021	Mar. 24, 2022
Cover [Abstract]
Document Type	10-K
Amendment Flag	false
Document Annual Report	true
Document Transition Report	false
Document Period End Date	Dec. 31, 2021
Document Fiscal Period Focus	FY
Document Fiscal Year Focus	2021
Current Fiscal Year End Date	--12-31
Entity File Number	001-14784
Entity Registrant Name	Income Opportunity Realty Investors, Inc.
Entity Central Index Key	0000949961
Entity Tax Identification Number	75-2615944
Entity Incorporation, State or Country Code	NV
Entity Address, Address Line One	1603 LBJ Freeway
Entity Address, Address Line Two	Suite 800
Entity Address, City or Town	Dallas
Entity Address, State or Province	TX
Entity Address, Postal Zip Code	75234
City Area Code	469
Local Phone Number	522-4200
Title of 12(b) Security	Common Stock
Trading Symbol	IOR
Security Exchange Name	NYSE
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Public Float	$ 6,600,000
Entity Common Stock, Shares Outstanding		4,168,414
Auditor Name	Swalm & Associates, P.C.
Auditor Location	Richardson, Texas
Auditor Firm ID	1820